What is the equation for calculating the heat energy released during heating effect of electric current?

Which changes of state do the labels represent? a: b: c:

Calculate the mass of an object that has a momentum of 100kg x m/sec and velocity of 4 m/sec

(a) assume the equation x = at^3 + bt describes the motion of a particular object, with x having the dimension of length and t having the dimension of time. determine the dimensions of the constants a and b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.) (b) determine the dimensions of the derivative dx/dt = 3at^2 + b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.)